1. Technical Field
The present disclosure concerns a transport apparatus for transporting at least one rotor blade of a wind power installation. In addition the present disclosure concerns an aid for improving the transport of a rotor blade of a wind power installation. In addition the present disclosure concerns a transport arrangement which transports at least one rotor blade of a wind power installation.
2. Description of the Related Art
Modern wind power installations are nowadays frequently a so-called horizontal axis rotor with a hub which generally faces into the wind (a windward rotor) and to which one or more and in particular three rotor blades are fixed. Such a rotor blade has—and this will also be taken as the basic starting point hereinafter—a rotor blade root for directly or indirectly fixing it to the hub. At the side remote from the rotor blade root the rotor blade has a rotor blade tip. In the region between the rotor blade root and the rotor blade tip the rotor blade is at least predominantly flat and has two sides which can be referred to as the suction side and the pressure side. In addition there are two edges which can also be referred to as the leading edge and the trailing edge. In accordance with its definition the leading edge faces substantially into the wind and is generally rounded whereas in normal operation of the wind power installation the trailing edge faces substantially away from the wind and is very thin and sometimes even a sharp edge to achieve an advantageous flow break-away effect.
Such rotor blades are nowadays of lengths of up to 60 m and greater lengths are certainly to be expected. Lengths of 35 to 40 m are nowadays certainly usual.
As state of the art, attention is generally directed at this point to the following documents: DE 36 04 496 A1, U.S. Pat. No. 7,374,405 B2, EP 1 813 473 A2, U.S. Pat. No. 6,286,435 B1 and WO 2006/000230 A1.
As far as possible such a rotor blade can be fixed and transported on a special transporter like a low loader on the corresponding load surface. If the length of the transporter is not sufficient the use of a transporter with a trailer can be envisaged. In that case the rotor blade is fixed and supported with its rotor blade root in the region of the tractor and the trailer is used in the region of the rotor blade tip. The trailer should then flexibly adapt to resulting movements of the rotor blade in the transport process. Such a trailer is therefore coupled to the tractor only by way of the item being transported—in this case the rotor blade.
The use of a transport vehicle with trailer is extremely complicated and is also often undesirable for other reasons. Particularly for transporting a rotor blade on the railways the use of a vehicle with a plurality of successively arranged and pivotably interconnected wagon elements is desired.
Such wagon elements, in particular railroad wagon cars, while moving, particularly on bends, perform movements relative to each other which do not have to correspond to the movements of a rotor blade supported thereon for transport thereof. In other words, to transport it, a rotor blade which is substantially longer than each of the specified wagon elements cannot be readily fixed at the same time on a plurality of wagon elements. The movement of the wagon elements relative to each other could lead to considerable stresses on the rotor blade and it could be damaged.
For that reason, a rotor blade can be arranged by means of special carriers which are respectively arranged on a wagon element, but in that case allow relative movements between the fixed rotor blade and the respective wagon element. Thus the rotor blade can be arranged with the rotor blade root on a carrier on a wagon element, that carrier permitting a rotary movement between the rotor blade and the wagon element. A further carrier can carry the rotor blade in a central region on another wagon element, in which case that second carrier permits both a rotary movement and also a translatory movement relative to that wagon element. In that respect it is to be noted that the wagon element on which the rotor blade root is mounted and the wagon element on which said middle region is supported does not have to be directly adjacent wagon elements but it is rather also possible to arrange a further wagon element between those two.
In that case the rotor blade tip is floating freely in space and is basically held only by the rotor blade itself. While travelling and depending on the respective boundary conditions involved, in particular the route but also the speed of travel, the rotor blade tip will move in relation to a wagon element, in the region of which it is for example disposed. Although it is assumed that at least when the situation is considered as virtually stationary, the movement of the rotor blade tip relative to said wagon element is so slight that the tip does not exit the internal region of the wagon element which is also referred to as the railway loading gauge (i.e., the region in which all items being transported have to be disposed when being transported), that nonetheless cannot be guaranteed because, for example, possible oscillation amplitudes to be expected are not accurately known.